Many medications and treatments, even after years of research, fail in the final phase of review — when they're actually tested in humans. Despite having performed well in the lab, in mice, and perhaps in closer human analogues like monkeys, drugs occasionally turn out to be ineffective or toxic when used by the humans they're meant to help. To improve this process, and limit the risks to human testers, the National Institutes of Health and the Defense Advanced Research Projects Agency are together pledging up to up to $132 million for creating "organ-on-a-chip" systems, with the eventual goal of simulating the entire human body.